Many attempts have been made to improve the comfort and chiropractic characteristics of pillows. One such attempt was development of a water pillow, as exemplified by U.S. Pat. No. 4,896,388 to Bard. The water pillow features a bladder within the pillow intended to be filled with water that then deforms to shape to the head of the user.
U.S. Pat. No. 7,017,214 to Bard described a variation on the water pillow in which flow was restricted within the bladder through a series of heat seal islands.
One of the drawbacks of the water pillow is that it provides little or no neck support since the localized downward pressure of the user's neck simply displaces the water in the bladder at that location.
Similar reference numerals may have been used in different figures to denote similar components.